Ever wonder why Java's const keyword is unimplemented? More specifically, why do we mark global constants in Java with both the static and final keywords? Why are Java constants static and final? The ...

See the Java 101 Java interfaces tutorial for a more in-depth introduction to using interfaces in your Java programs, including where and where not to use default, static, and private methods.

The former method is executed by default methods a() and b(), and the latter method is executed by static method d(). Compile Listing 21 (javac PMDemo.java) and run the application (java PMDemo).